# Using the same numbering in two different {chapter*}

I'm currently writting my thesis and I have to record two introductions (environment \chapter*) : one in French and one in English. Since the informations and equations are exactly the same, I would like to use the same numerotation for both chapter. But it seems like latex considers that the two environments chapter* belong to the same chapter.

Do you have any idea to fix my problem? This is an example:

\documentclass[a4paper,10pt,french,reqno]{amsbook}
\usepackage[utf8x]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[reqno]{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage[english]{}
\usepackage{hyperref}

\numberwithin{equation}{chapter}

\begin{document}
\mainmatter

\chapter*{French}
\section{Section 1}
$$\label{eq1_FR} x=y$$
La première équation \eqref{eq1_FR}.

\chapter*{English}
\stepcounter{chapter}
\section{Section 1}
$$\label{eq1_EN} x=y$$
I cite the first equation \eqref{eq1_EN} of the chapter "English", but the hyperref sends me to the equations \eqref{eq1_FR}, even if there are well labeled.

\chapter{First chapter}

$$\label{chap1} x=y$$

There is no problem for this equation \eqref{chap1}.
\end{document}


Thanks!

• Welcome to TeX.SX! Maybe \setcounter{equation}{0} after the second \chapter*? – egreg Sep 10 '18 at 9:47
• One solution could be to reset the counter for equations \setcounter{equation}{0}. But I don't know if this is a good solution. – faltfe Sep 10 '18 at 9:48
• I haven't tested this, but: If, after \begin{chapter*}, you insert \stepcounter{chapter}, then all the counters that should be reset at a chapter start should be reset. Follow it by \addtocounter{chapter}{-1} in order not to mess up chapter numbering. Of course, if \theequation, \thesection and so on contain a reference to the chapter number, you have a bigger problem. But I trust you realize that, and know what to do if so. (If this works, let me know in a comment, and I'll convert it to an answer.) – Harald Hanche-Olsen Sep 10 '18 at 11:02
• First of all, thanks a lot for your help! All of these solutions works fine, and it gives the right numerotation. However, the hyperlink of an equation in the second introduction (\eqref{intro2:eq1}) leads me to the right equation but in the first introduction (\label{intro1:eq1}). I have the same problem for the hyperlink of the sections, but not for the hyperlink of the figures. Yes, this lacks logic! – Norah Sep 11 '18 at 13:11
• @Norah You have to use different labels in both sections, for example \label{intro1:eq1:english} and \label{intro1:eq1:french} – user36296 Sep 17 '18 at 14:30

From the example document, I assume that English is the main language.

In order to reset the counters related to chapter, the strategy is to issue \stepcounter{chapter}, accompanied by \addtocounter{chapter}{-1} to keep the number to zero.

For hyperref one can locally redefine \theHchapter so to give unique anchors in the French part.

\documentclass[a4paper,10pt,reqno]{amsbook}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}        % not utf8x
\usepackage[french,english]{babel} % english is the main language
%\usepackage[reqno]{amsmath}       % redundant with amsbook
%\usepackage{amsfonts}             % redundant with amssymb
\usepackage{amssymb}
%\usepackage{amsthm}               % redundant with amsbook

\usepackage{hyperref}

\numberwithin{equation}{chapter}

\begin{document}
\mainmatter

\begin{otherlanguage}{french}
\renewcommand{\theHchapter}{FR\thechapter}

\chapter*{French}
\section{Section 1}
$$\label{eq1_FR} x=y$$
La première équation \eqref{eq1_FR}.

\end{otherlanguage}

\stepcounter{chapter}

\chapter*{English}
\section{Section 1}
$$\label{eq1_EN} x=y$$
I cite the first equation \eqref{eq1_EN} of the chapter "English",
but the hyperref sends me to the equations \eqref{eq1_FR},
even if there are well labeled.

\chapter{First chapter}

$$\label{chap1} x=y$$

There is no problem for this equation \eqref{chap1}.

\end{document}


Note that utf8x has been unmaintained for several years and that, on the contrary, utf8 is actively maintained and developed by the LaTeX team.

• Thanks a lot, this works fine. I also take into account your remark on utfx8 ! – Norah Sep 25 '18 at 13:22